View Full Version : Laptop Clear CMOS

12-06-2000, 04:16 PM
Hello there,

on a laptop, FIC DesigNote 6100, the bios is password-protected but no-one knows the password.
I looked for a clear cmos jumper but wasn't able to find one. Does anyone know how to remove the password / how to enter the bios again ?


12-06-2000, 05:02 PM
Look for a battery. My NEC has a watch battery on the motherboard.

12-06-2000, 05:24 PM
Nope, I wasn't able to find a battery there. Nevertheless there has to be one, because the password keeps saved.
Is there any "special" location for batteries in laptops ?
How do they look like ? I only know the desktop pc's batteries. But I couldn't find any removable thing there.


12-06-2000, 09:09 PM
isn't there a DOS based program that will clear the CMOS password for you?

12-07-2000, 12:09 AM
check your manual for this, my laptop has a keyboard combination for this.

12-07-2000, 07:42 AM
On some laptops, the main battery is also used as the CMOS battery. Try removing the battery while the machine is not plugged in to AC. Wait about 15 minutes or so. Put the battery back in and fire it up.

That could clear your BIOS.

Works for mine....

12-07-2000, 10:26 AM
Just a note of caution (don't laugh either :D )--I killed my Fujitsu laptop trying to find the battery to clear a password that I never set. Of course, you may know your way around inside a laptop. I didn't. As far as I know though, I didn't do anything I wasn't supposed to, but when I got done and restarted it, it wouldn't do anything. So, all that said, I'm saying this-unless you want to turn your laptop into a big pile of spare parts, be very careful while poking around inside.

12-07-2000, 11:09 AM
Thank you all for your replies.
Lovits, I found a tool that cleared cmos. I had to reset the settings, but finally the password is gone :)
Thank you.
And, UncaDanno, I also tried that, but didn't help. Well, now it's over.


12-07-2000, 04:41 PM
well I'm glad to help. :)

12-08-2000, 02:20 PM
Well, and BTW, I also found source code to clear cmos. WOW ! That's easy !! I never knew that with 2 lines of code I can reset the whole CMOS to factory defaults. Now I have my own program, just for emergency ;)
I now think I'll never have that problem a second time.

Thanks again,


Black Ice
07-12-2001, 06:40 PM
what was the two lines of code

07-12-2001, 06:44 PM
yeah share it with us

jr mb working great.

07-13-2001, 07:36 AM
Gosh ! I couldn't believe my eyes when I opened the "PC Hardware" section and then saw my old thread :eek:

How did you find this ???

Well, the two lines of code are actually:

Write 17 decimal to port 70 hex
Write 0 to port 71 hex

In Pascal it would be:

program clear_cmos;


Of course that means that you have to be able to boot. If you need that password to boot then you can't do this.

Have fun.


07-29-2001, 02:09 PM
Of course that means that you have to be able to boot. If you need that password to boot then you can't do this.


So, what if you can't even boot then? I have tried to remove battery and it seems to be spot welded in (seems anyway) and I really don't want to break anything... It's an old Packard Bell and I have no book, cant seem to find any jumpers that look like they would clear the bios.

Any ideas?

07-29-2001, 02:15 PM
If you can't find the jumper then the only chance is to remove the battery.
Remove it and keep it outside. You won't damage anything, just the cmos settings will get lost. Same as with these 2 lines of code.

If your mainboard can save data over a longer period of time then you can take the battery out and shorten the two battery contacts (+ and -) on the board with a 10k-Ohm resistor. Of course the PC has to be turned off and disconnected from power when doing this.
That should take care of the password. If this doesn't help, then I don't know what else would.


07-29-2001, 03:36 PM
Rj, Thanks for your quick reply. I found what I needed to on this website:


It is an informative site FULL of Packard Bell info. These machines are such a pain in the a*s I have bookmarked it for future references while working with this crap. Thanks again!

11-28-2005, 08:47 AM
Although some fic laptops have a dip switch setting to remove the password it is rare, almost no laptops store the password in the bios, and removing the battery will not help.

The password is normally stored in a seperate 8 or 14 pin security chip I will provide a list next.

on some systems you can simply get away with replacing the chip with a blank, but on some Ie. the hp 6000 the chip also has information about other items ie in the 6000 the lcd model, if you replace with a blank that part of the system will stop working

As a rough guide the following are chip numbers for various models

On laptops, the password is usually stored in an eeprom on the motherboard,
you need an eeprom programmer (electronic device) to retrieve it.

Acer 630: eeprom 93c56 ?
Compaq M700: eeprom 24C02
Dell Inspirion 7500: eeprom 24c164
Dell Inspirion 8100: eeprom 24c02
Dell Latitude C600: eeprom 24c02, password in scan code at 0x00, 0x10 and 0x90
Dell Latitude C610: eeprom 24c02, password in scan code at 0x00, 0x10, 0x80 and 0x90
Dell Latitude CPI: eeprom 24c02, password in scan code at 0x00, 0x10, 0x80
IBM Thinkpad X20: eeprom 24RFC08CN, password in scan code at 0x338
IBM TP 240: eeprom ?, password in scan code at 0x338.
IBM TP 380Z: eeprom 24c01, password in scan code at 0x38 and 0x40
IBM TP 390: eeprom 24c03 (be carrefull, there are two eeprom)
IBM TP 560X: eeprom 24c01, password in scan code at 0x38 and 0x40
IBM TP 570: eeprom ?, password in scan code at 0x338 and 0x3B8.
IBM TP 750C,755CX,760C,765D: eeprom 93c46, password in scan code at 0x38 and 0x40
OKI M811b may be written on the chip. Search near pcmcia slot or
adjacent the floppy connector on the top side of the board
IBM TP 770: eeprom 24c01
IBM TP 600E, T21, T23: 14 PIN 24RF08
IBM TP T20: 24RF08, password in scan code at 0x338 and 0x3B8
HP Omnibook 900,2100,4150,7150: eeprom AT24c164, 0x6D-0x7F area, unknow algo
put a 00 at 0x7F to clear admin password
HP Omnibook 6000: eeprom 24c08 or 24c164 0x50-0xBF area
(maybe 0x50-0x6F only), unknow algo
HP Omnibook 6100: eeprom 24c08
HP Omnibook XE3: eeprom 24c16
HP Omnibook 770x: eeprom 24c01
HP Pavilion ze4455ea: eeprom 24c08
HP VECTRA VL18: http://h200001.www2.hp.com/bc/docs/support/SupportManual/lpv06673/lpv06673.pdf
Sony pcg-fx950: eeprom 93c46 ?
Toshiba 74600C: eeprom 93c56
VAIO 641: eeprom 24c02, write zero at 0x0
be carrefull, there are two eeprom you must unsolder one to the pci
controler it is in the down side of the bord

VAIO 8851
eeprom 24c02 (ic 903), write zero at adress 0x0
the down side of the board

VAIO srx 87: eeprom 2408, write zero at 0x0
the ic is behind the modem in the top side of the board

Acer machines do tend to have a jumper setting and earlier toshibas can be disabled with the toshiba loopback.

Loopback for toshiba wiring below

parallell wire with 25pins connectors (db25). You should connect
these pins: 1-5-10, 2-11, 3-17, 4-12, 6-16, 7-13, 8-14, 9-15, 18-25

We have been trading and used to repair laptops of all brands on the web for 15 years, and are pretty well the most knowledgable on this subject.

anyone that says take the battery out probably has no idea, it works on most desktops but not on laptops

Panama Red
11-28-2005, 09:58 AM
sysserv, pulling up 5 year old threads in order to post a referral to your personal web site is considered "spamming" and not allowed here. I'm removing the links from the first post and removing the second post in it's entirety. Reposting this information will result in an immediate ban or your account.